Phenylacetonitrile → alpha-(1-(Phenylmethyl)piperidin-4-ylidene)phenylacetonitrile

Participants

Reaction Steps

To a solution sodium ethoxide is added benzyl cyanide and N-benzyl-4-piperidone (XI-1) and the reaction is run at 85° C. for 3 h. Workup with concentrated hydrochloric gives the intermediate (1-benzyl-piperidin-4-yl-idene)-phenyl-acetonitrile which is treated with potassium cyanide. Reduction of one carbonyl group is performed with an excess of diisobutylaluminium hydride and elimination is performed with acetic acid. The obtained intermediate N-benzyl protected spiropiperidine is treated with hydrogen and palladium on charcoal. After stirring in a hydrogen atmosphere at room temperature (CF3)2C6H3COCl is added to give a compound of formula I-13.

Provenance & Evidence